Active Storage Variants with Rails 6.1

The Error!

Upgrading to Rails 6.1 and encountering the following error?

ActiveRecordNotNullViolation (PGNotNullViolation: ERROR: null value in column “record_id” of relation “active_storage_attachments” violates not-null constraint)

Let me save you a couple hours!

Lets back up a step. Are you using t.uuid :record_id (is your record_id for ActiveStorage a uuid?)

If you’re not sure, you can check your db/schema.rb

```rb title=db/schema.rb create_table “active_storage_attachments”, force: :cascade do |t| # … t.uuid “record_id”, null: false # … end

If yes, keep reading. If not, sorry, this wont be much help.

<h2 id="using-uuid-me-too">
  <a href="#using-uuid-me-too">
    Using UUID for record_id, cool I was too
  </a>
</h2>

Alright now that we've located the source how do we fix it?

When you run `rails app:update` or `rails active_storage:update` it will
create 2 migrations for you. In particular we want to look at the one
generating the `active_storage_variant_records` table. The file should look
something like this:

```rb title=db/migrate/xxxx_create_active_storage_variant_records.active_storage.rb
class CreateActiveStorageVariantRecords < ActiveRecord::Migration[6.0]
  def change
    create_table :active_storage_variant_records do |t|
      t.belongs_to :blob, null: false, index: false
      t.string :variation_digest, null: false

      t.index %i[ blob_id variation_digest ], name: "index_active_storage_variant_records_uniqueness", unique: true
      t.foreign_key :active_storage_blobs, column: :blob_id
    end
  end
end

From here the fix is just to add a uuid constraint for the id like so:

```diff title=db/migrate/xxxx_create_active_storage_variant_records.active_storage.rb class CreateActiveStorageVariantRecords < ActiveRecord::Migration[6.0] def change

create_table :active_storage_variant_records do t
create_table :active_storage_variant_records, id: :uuid do |t|
…

end end ```

Now rollback your migrations, rerun your migrations, and onward to victory!!

Active Storage Variants with Rails 6.1

The Error!

…

Links

Active Storage docs

Rails 6.1 migration docs